DEN the arrival is mated with the runway. When it changes, it all changes in one stroke well prior to the arrival controller reaching blindfolded into the bag of runways. There's no guessing just reacting. I hate ATL for a myriad of reasons including no heading requests on departure to give yourself the requisite 5 mile spacing from weather. What "extenda" marvels at is the fact that 90% of the time they get 10lbs of sh!t to fit in the 5lbs bag. But when all their stuffing explodes the bag, sh!t goes everywhere. Then pilots are blamed and have to cleanup the sh!t. No buffers is the problem not the solution.